chore: fix some comments (#4937)

Fixture for some English comments in syntax.

Co-authored-by: Maledong <maledong_github@outlook.com>

lib/application.js

@@ -127,7 +127,7 @@ class Application extends EggApplication {
     if (typeof this.config.onClientError === 'function') {
       const p = eggUtils.callFn(this.config.onClientError, [ err, socket, this ]);
 
-      // the returned object should like:
+      // the returned object should be something like:
       //
       //   {
       //     body: '...',

lib/core/dnscache_httpclient.js

@@ -71,7 +71,7 @@ class DNSCacheHttpClient extends HttpClient {
 
     args = args || {};
     args.headers = args.headers || {};
-    // set host header is not exists
+    // set when host header doesn't exist
     if (!args.headers.host && !args.headers.Host) {
       // host must combine with hostname:port, node won't use `parsed.host`
       args.headers.host = parsed.port ? `${hostname}:${parsed.port}` : hostname;
@@ -81,7 +81,7 @@ class DNSCacheHttpClient extends HttpClient {
     const now = Date.now();
     if (record) {
       if (now - record.timestamp >= this.dnsCacheLookupInterval) {
-        // make sure next request don't refresh dns query
+        // make sure the next request doesn't refresh dns query
         record.timestamp = now;
         this[UPDATE_DNS](hostname, args).catch(err => this.app.emit('error', err));
       }

test/app/extend/request.test.js

@@ -272,13 +272,13 @@ describe('test/app/extend/request.test.js', () => {
         expectQueries('a[]=&a[]=b&a=foo', { 'a[]': [ '', 'b' ], a: [ 'foo' ] });
         expectQueries('a=bar&a[]=&a[]=b&a=foo', { 'a[]': [ '', 'b' ], a: [ 'bar', 'foo' ] });
 
-        // a[][] 这种不支持自动变化为 a
+        // 'a[][]' doesn't support converting to 'a'
         expectQueries('a[][]=&a[][]=b', { 'a[][]': [ '', 'b' ] });
         expectQueries('a][]=&a][]=b', { 'a][]': [ '', 'b' ] });
         expectQueries('a[[]=&a[[]=b', { 'a[[]': [ '', 'b' ] });
         expectQueries('[]=&[]=b', { '[]': [ '', 'b' ] });
 
-        // a[], a 混搭的时候，只返回最后一个 a 的值
+        // 'a[]' only returns the last value when mixed with others
         expectQueries('a[]=a&a=b&a=c', { 'a[]': [ 'a' ], a: [ 'b', 'c' ] });
 
         // object

test/async/index.test.js

@@ -1,7 +1,7 @@
 'use strict';
 
 const nodeVersion = Number(process.version.match(/^v(\d+\.\d+)\./)[1]);
-// only node >= 7.6 support async function without flags
+// only node >= 7.6 supports async function without flags
 if (nodeVersion >= 7.6) {
   require('./_async');
 }

test/bench/server.js

@@ -15,7 +15,7 @@ app.ready().then(() => {
   console.log('app(%s) ready', app.config.baseDir);
 
   const server = http.createServer(app.callback());
-  // emit server event just like egg-cluster does
+  // emit server event just like egg-cluster
   // https://github.com/eggjs/egg-cluster/blob/master/lib/app_worker.js#L52
   app.emit('server', server);
 

test/lib/application.test.js

@@ -79,7 +79,7 @@ describe('test/lib/application.test.js', () => {
         assert(err.message === 'Please set config.keys first');
       }
 
-      // make sure app close
+      // make sure app closed
       await app.close();
     });
 
@@ -96,7 +96,7 @@ describe('test/lib/application.test.js', () => {
         assert(err.message === 'Please set config.keys first');
       }
 
-      // make sure app close
+      // make sure app closed
       await app.close();
     });